1. Field of the Invention
This invention relates to multistatic radar systems and is capable of increasing the observable range thereof.
2. Prior Art
Multistatic radar systems have hitherto been used in various configurations, such as those shown in FIGS. 1 and 2 of the drawings. Such configurations are shown, for example, in FIG. 6 of Chapter 36, "Bistatic and Multistatic Radar" of RADAR HANDBOOK, published by McGraw-Hill Inc.
The conventional radar system shown in FIG. 1 employs a transmitter means 1 for radiating high-frequency radio waves and receiver means 2, 3 for detecting a target 4. The conventional radar system shown in FIG. 2 also employs transmitter means 1, 5 and receiver means 2, 3, 6 in order to locate the target 4. In both the systems, the transmitter means 1, 5 and the receiver means 2, 3, 6 are placed on the ground.
The radar system of FIG. 1 is operated in such a manner that high-frequency radio waves radiated from the transmitter means 1 are directed to and reflected by the target 4, and the reflected waves are received by the receiver means 2 and 3 which locate and track the target 4 on the basis of the received waves. If the target 4 exists behind a mountain or below the horizon, however, the emitted radio waves would not reach the target 4 so making it impossible to search and track the target 4.
The radar system of FIG. 2 is also operated so that high-frequency radio waves radiated from both the transmitter means 1 and 5 are directed to and reflected by the target 4, and the reflected waves are received by the receiver means 2, 3 and 6 which locate and track the target 4 using the received waves. Again the radiated radio waves cannot reach the target 4, when the target is behind a mountain or below the horizon.
Such conventional multistatic radar systems as described above have drawbacks such that the target-searching and tracking ranges per one transmitter means are limited and it is required to place a number of transmitter means at different sites.